Hi,
I'm using WMI to start a process on a remote machine. The call to create the process returns immediately and I also get the id of the process on the remote machine.
I would like to wait for the remote process to be completed. One option would be to poll whether a process on the remote machine with the given id still exists.
However, I was wondering whether there is a better way to achieve this, maybe using native WinAPI functions?
Just for additional information, this is the code that I am currently using to start the remote process:
ConnectionOptions connOptions = new ConnectionOptions();
connOptions.Impersonation = ImpersonationLevel.Impersonate;
connOptions.EnablePrivileges = true;
connOptions.Username = domainUserName;
connOptions.Password = password;
ManagementScope manScope = new ManagementScope(String.Format(@"\\{0}\ROOT\CIMV2", host), connOptions);
manScope.Connect();
ObjectGetOptions objectGetOptions = new ObjectGetOptions();
ManagementPath managementPath = new ManagementPath("Win32_Process");
ManagementClass processClass = new ManagementClass(manScope, managementPath, objectGetOptions);
ManagementBaseObject inParams = processClass.GetMethodParameters("Create");
inParams["CommandLine"] = commandLine;
ManagementBaseObject outParams = processClass.InvokeMethod("Create", inParams, null);
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The native Win32 way of achieving this would be to perform a
WaitForSingleObject()
on the process handle returned byCreateProcess()
, however I don't think this handle is made available to you from WMI.This article offers another option you could consider - instead of polling the process list and waiting for your process to disappear, it repeatedly queries for process deletion events matching your process ID:
strComputer = "." Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2:Win32_Process") objWMIService.Create "notepad.exe", null, null, intProcessID Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2") Set colMonitoredProcesses = objWMIService.ExecNotificationQuery _ ("Select * From __InstanceDeletionEvent Within 1 Where TargetInstance ISA 'Win32_Process'") Do Until i = 1 Set objLatestProcess = colMonitoredProcesses.NextEvent If objLatestProcess.TargetInstance.ProcessID = intProcessID Then i = 1 End If Loop
You could also improve on this by using a
ManagementEventWatcher
object and itsWaitForNextEvent
method to avoid having to poll for the deletion events. -
I don't know how effective this can be, you can use ManagementEventWatcher to watch a query.
Here is something I found on the net.
WqlEventQuery wQuery = new WqlEventQuery("Select * From __InstanceDeletionEvent Within 1 Where TargetInstance ISA 'Win32_Process'"); ManagementEventWatcher wWatcher = new ManagementEventWatcher(scope, wQuery); bool stopped = false; while (!stopped) { ManagementBaseObject MBOobj = wWatcher.WaitForNextEvent(); if (((ManagementBaseObject)MBOobj["TargetInstance"])["ProcessID"].ToString() == ProcID) { // the process has stopped stopped = true; } } wWatcher.Stop();
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If the process on the remote machine is your code then you could open up a socket on the calling machine and let the remote machine 'ping' it when it has finished.
If you want to use this method for any remote process you could have a helper app/service on the remote computer that monitors your process and returns the completed ping.
0xA3 : That's a nice idea, thanks. This would probably be most efficient and quite simple. However, I would like to keep it as generic as possible so I can start any process remotely.
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